CN110177980B

CN110177980B - Performance diagnostic device and performance diagnostic method for air conditioner

Info

Publication number: CN110177980B
Application number: CN201780083310.6A
Authority: CN
Inventors: 国眼阳子; 楠本宽; 藤居达郎
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2017-03-10
Filing date: 2017-03-10
Publication date: 2021-08-27
Anticipated expiration: 2037-03-10
Also published as: US20190316798A1; CN110177980A; JP6750091B2; WO2018163402A1; JPWO2018163402A1; US10989428B2

Abstract

The performance diagnosis device for an air conditioner of the present invention comprises: a data collection unit for collecting and recording operation data of the air conditioner; an equipment characteristic database which is a data group for collecting operating conditions that satisfy the specifications of an air conditioner, the equipment characteristic database further comprising: a reference data creating unit for calculating individual characteristic curved surface data using the operation data and the equipment characteristic database included in the data collecting unit; and a performance evaluation unit that compares a part of the operation data of the data collection unit with the individual characteristic curved surface data, which is obtained by correcting the equipment characteristic database so as to correspond to the operation data of the data collection unit, and evaluates the performance of the air conditioner. Thus, the performance deterioration of the air conditioner can be detected regardless of the magnitude of the air conditioning load, and it is possible to clarify whether or not the maintenance work of the air conditioner is required.

Description

Performance diagnostic device and performance diagnostic method for air conditioner

Technical Field

The present invention relates to a performance diagnosis device and a performance diagnosis method for an air conditioner.

Background

As devices for cooling large-scale spaces such as various factories and buildings, heat-driven refrigerators and electric refrigerators are used. The consumption of primary energy of the refrigerator accounts for about two to three times of the total building, and therefore, in recent years, energy saving is particularly demanded.

In general, a refrigerator controls a cooling output according to a required cooling load, and the output is changed in a complicated manner such as being large in the midsummer of 7 and 8 months and being small in the middle of 5 and 10 months.

In addition, since the refrigerator is supposed to be used for a long period of time, it is important to maintain system performance over the years, not only to select efficient equipment at the time of installation, but also to save energy. Since the above-described refrigerator includes a water circuit for supplying cold and hot water from the refrigerator to the space to be cooled, and a cooling water circuit for radiating heat entering the refrigerator or heat in the space to be cooled, scale or the like adheres to the pipes over the course of years, and the equipment itself deteriorates. In order to maintain a predetermined system performance, it is necessary to eliminate the performance deterioration by a regular maintenance work.

Patent document 1 discloses a refrigerator deterioration diagnosis apparatus and a refrigerator deterioration diagnosis method, which aim to accurately divide piping cleaning and overhaul as the content of maintenance to be performed on deterioration of the performance of a refrigerator, calculate an estimated actual COP and an estimated actual LTD indicating actual performance under an estimated operating condition based on estimated operating condition data, calculate a COP variation indicating a difference between the estimated actual COP and an estimated reference COP, and calculate an LTD variation indicating a difference between the estimated actual LTD and the estimated reference LTD, and divide the situation based on whether or not a variation ratio R between the COP variation at the time of estimation and the LTD variation is constant within a determination region Q. Here, LTD is an abbreviation of Leaving Temperature Difference (Leaving Temperature Difference) which is one of indexes of cooling efficiency of a refrigerator. Patent document 1 also discloses an explanatory diagram (fig. 6) showing a reference COP estimation model, which is a curved surface in a band shape in a three-dimensional space.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-205640

Disclosure of Invention

Problems to be solved by the invention

If maintenance work involving the operation stop of the air conditioner is performed during the midsummer period when the cooling load is large or during the severe winter period when the heating load is large, the comfort in the building to be cooled or heated (air-conditioning) is significantly impaired, and therefore it is preferable to predict the time when the performance degradation occurs in advance and perform the maintenance work during the spring and autumn periods when the air-conditioning load is small. Of course, when only the cooling operation is performed without the heating operation, the cooling operation may be performed in a no-load state such as a winter period.

Patent document 1 describes in a general way that the operating condition data of the refrigerator obtained before the evaluation time can be used for the creation of a reference COP estimation model used for the degradation diagnosis of the refrigerator. However, patent document 1 does not disclose a concept of using the operating condition data of the refrigerator in order to detect performance deterioration when the cooling load is small.

Even if the same type of refrigerator (air conditioner) differs in performance depending on the installation location and the operating condition, it is difficult to determine whether the deviation between the evaluation parameter calculated from the operation data obtained during actual operation and the specification data (evaluation parameter) is due to deterioration or measurement error, particularly when the cooling load is small.

The invention aims to: regardless of the magnitude of the air conditioning load, the performance degradation of the air conditioner is detected, and it is clarified whether or not the maintenance work of the air conditioner is necessary.

Means for solving the problems

The performance diagnosis device for an air conditioner of the present invention comprises: a data collection unit for collecting and recording operation data of the air conditioner; an equipment characteristic database which is a data group for collecting operating conditions that satisfy the specifications of an air conditioner, the equipment characteristic database further comprising: a reference data creating unit for calculating individual characteristic curved surface data using the operation data and the equipment characteristic database included in the data collecting unit; and a performance evaluation unit that compares a part of the operation data of the data collection unit with the individual characteristic curved surface data, which is obtained by correcting the equipment characteristic database so as to correspond to the operation data of the data collection unit, and evaluates the performance of the air conditioner.

Effects of the invention

According to the present invention, it is possible to detect the performance degradation of the air conditioner regardless of the magnitude of the air conditioning load, and to determine whether or not the maintenance work of the air conditioner is necessary.

Drawings

Fig. 1 is a block diagram showing a configuration of a performance evaluation server according to an embodiment.

Fig. 2 is a schematic configuration diagram showing the configuration of the refrigerator and the arrangement of the measurement sensors according to the embodiment.

Fig. 3 is a table showing an example of the device characteristic database of the embodiment.

Fig. 4 is a graph showing a time-series change in fouling of a general heat transfer pipe.

Fig. 5 is a flowchart showing a processing procedure of the reference data creating unit according to the embodiment.

Fig. 6 is a three-dimensional graph showing an example of the individual characteristic curved surface of the embodiment.

Fig. 7 is a table showing an example of the structure of the evaluation parameters of the embodiment.

Fig. 8 is a flowchart showing the processing procedure of the system performance evaluation unit according to the embodiment.

Fig. 9 is a graph showing an example of a screen as a result of performance evaluation output as an example.

Detailed Description

The performance diagnostic device and the performance diagnostic method for an air conditioner according to the present invention are suitable as a technology for monitoring an air conditioner from a remote place.

In the following description, the cooling operation of the refrigerator is mainly described, but in the case of a heat pump capable of performing not only the cooling operation but also the heating operation, it is necessary to consider an air conditioning load in which the cooling operation and the heating operation are combined. In the present specification, a technique applicable to both the cooling operation and the heating operation is disclosed. A refrigerator, a heat pump, and the like are collectively referred to as an "air conditioner". The air conditioning duty described later indicates a duty of an air conditioner that performs at least one of a cooling operation and a heating operation.

The air conditioner may be of any of an electric type and a heat-driven type.

An electric air conditioner includes an electric compressor. On the other hand, examples of the heat-driven air conditioner include an absorption refrigerator, an absorption heat pump, an adsorption refrigerator, and an adsorption heat pump. The heat source of the heat-driven air conditioner is combustion heat of gas, oil, or the like, plant exhaust heat, or the like.

Hereinafter, a performance diagnosis apparatus and a performance diagnosis method for an air conditioner (freezer) according to an embodiment of the present invention will be described in detail with reference to the drawings.

Examples

Fig. 1 is a block diagram showing the configuration of a performance evaluation server according to the present embodiment. Fig. 2 shows an example of the structure of a refrigerator to be evaluated for performance.

First, the configuration of the performance evaluation server in fig. 1 will be described.

The performance evaluation server 1 (performance diagnosis device) of the refrigerator 3 is connected to the refrigerator 3 via the operation data monitor 2 as a transmitter. The operation data acquired by the operation data monitor 2 includes a signal from a sensor provided in the refrigerator 3 and also includes raw data obtained from the refrigerator 3 that is actually operating. In the present embodiment, the turbo refrigerator is assumed as the refrigerator 3, and details of the configuration will be described later with reference to fig. 2.

The performance evaluation server 1 is provided with a main storage device 10 (first storage means), a sub-storage device 11 (second storage means), an interface 12, a CPU13 (central processing unit), an input device 14 (input means), and an output device 15 (output means), and diagnoses a change in performance of the refrigerator 3. The main storage device 10 includes a data collection unit 10A, a reference data creation unit 10B, a system performance evaluation unit 10C (performance evaluation unit), and an output unit 10D. Further, the first storage unit and the second storage unit may be collectively referred to simply as "storage unit".

The data collection unit 10A has a function of measuring data corresponding to a desired evaluation parameter via a sensor provided in the refrigerator 3, and a function of recording the measured time-series data as history data.

The sub storage 11 stores a device characteristic database.

Fig. 2 is a configuration diagram showing an example of the arrangement of the measurement sensors when the structure of the refrigerator 3 and the performance evaluation server are applied. This embodiment shows a case where the refrigerator 3 is a turbo refrigerator.

The turbo refrigerator mainly includes a refrigerant circuit formed by connecting a turbo compressor 21 powered by an electric motor 20, a condenser 22, an expansion mechanism 23, and an evaporator 24 in this order by refrigerant pipes.

As the measurement sensors, a cold water inlet temperature sensor 24b, a cold water outlet temperature sensor 24c, a cooling water inlet temperature sensor 22b, a cooling water outlet temperature sensor 22c, a cold water flow meter 24a, and a cooling water flow meter 22a are provided at each point.

Cold water is generated by the evaporator 24 so that the temperature measured by the cold water outlet temperature sensor 24c becomes a predetermined value. The cold water is sent to a space 27 to be cooled (e.g., an indoor space of a building) by the power of the water circulation pump 28, and absorbs heat from the space 27 to be cooled. The cold water having absorbed heat and increased in temperature exchanges heat with the refrigerant in the evaporator 24 to be cooled. The refrigerant in the evaporator 24 is sent to the condenser 22 through the refrigerant pipe, and is radiated to the cooling water. The cooling water is sent to the cooling tower 26 by the water circulation pump 25. In the cooling tower 26, the cooling tower fan 26a is controlled so that the temperature measured by the cooling water inlet temperature sensor 22b becomes a predetermined value, and the heat of the cooling water is radiated to the atmosphere.

The equipment configuration and operation of the refrigerator 3 shown in fig. 2 are merely examples, and the performance evaluation server 1 of the refrigerator according to the present embodiment is not limited to the operation principle, arrangement, and the like of the refrigerator to be evaluated.

The reference data creating unit 10B in fig. 1 has a function of creating data of system performance in a state where degradation of the refrigerator 3 does not occur in the entire assumed operating range, using the equipment characteristic database stored in the sub storage device 11 and a part of the data stored in the data collecting unit 10A.

Fig. 3 shows an example of data included in the device characteristic database.

The equipment characteristic database is a group of data that collects operating conditions that satisfy the specifications of the refrigerator. The equipment characteristic database may be a structure summarized by using design values of the refrigerator, results of quality confirmation tests measured by using a testing machine before shipment in order to be published in specifications issued by a manufacturer of the refrigerator, and the like. The COP (Coefficient of Performance) corresponding to the system Performance of the refrigerating machine varies depending on the air conditioning load factor, the cooling water inlet temperature, the cold water outlet temperature, and the like, but in the present figure, the cooling water outlet temperature is fixed, and the air conditioning load factor (hereinafter also simply referred to as "load factor"), the COP, and the cooling water inlet temperature are set as evaluation parameters and obtained by sorting the parameters in accordance with 3 axes of the X axis, the Y axis, and the Z axis.

As shown in the figure, if comparison is made when the load factors are equal, the COP increases under the condition that the inlet temperature of the cooling water is low (spring, autumn, and winter). On the other hand, under the condition (summer) where the cooling water inlet temperature is high, the COP decreases.

In addition, although the evaluation target of the present embodiment is a water-cooled refrigerator, in an air-cooled refrigerator that does not require cooling water, the ambient air temperature of the condenser may be used as the evaluation parameter instead of the cooling water inlet temperature.

Here, the air conditioning duty is a value obtained by dividing the amount of heat processed by the indoor unit by the rated capacity of the air conditioner, and is a value obtained by dividing the difference between the cold water outlet temperature and the cold water inlet temperature of the refrigerator in actual operation by the difference between the cold water outlet temperature and the cold water inlet temperature set as the design value of the refrigerator when cold water is cooled by the evaporator and supplied to the indoor unit during the cooling operation. Specifically, in fig. 2, the values measured by the cold water inlet temperature sensor 24b and the cold water outlet temperature sensor 24c are used as the inlet temperature and the outlet temperature of the cold water cooled by the evaporator 24, respectively, and calculated.

In general, in the case of a compression-type refrigerator (heat pump), heating operation is performed using heat generated by a condenser. In this case, the air conditioning duty is a value obtained by dividing the difference between the hot water outlet temperature and the hot water inlet temperature of the heat pump that is actually operating by the difference between the hot water outlet temperature and the hot water inlet temperature that is set as the design value of the heat pump when the hot water is heated by the condenser and supplied to the indoor unit. In the case of performing a heating operation of a compression-type refrigerating machine (heat pump) using air as a heat medium circulating through an indoor unit and a condenser, temperatures of air on the upstream side and the downstream side of the condenser are measured as an inlet temperature and an outlet temperature, respectively, and an air conditioning duty is calculated by the same calculation as in the case of warm water.

In the case of heating operation of the absorption heat pump, the air conditioning duty is a value obtained by dividing an average value of a difference between a warm water outlet temperature and a warm water inlet temperature of the absorption heat pump that is actually in operation by a difference between the warm water outlet temperature and the warm water inlet temperature that is set as a design value of the absorption heat pump, with respect to warm water returned from the indoor unit, in order to heat warm water by heat generated by at least one of the condenser and the absorber and send the heated warm water to the indoor unit to thereby perform heating.

However, even in a state where the system performance at the initial stage of installation is not degraded, the actual system performance of the refrigerator is generally lower than the device characteristic data due to the influence of the installation situation and the like. In the present embodiment, in order to accurately grasp the system performance in a state where each device is not degraded, the device characteristic data is corrected using a part of the data stored in the data collection unit 10A, and the individual characteristic curved surface is created.

Most of the causes of deterioration of system performance of the refrigerator are the adhesion of scales and the like to the inside of a heat transfer pipe for cooling water or cold water. In the heat transfer pipe, minerals and the like in water are crystallized and accumulated as scale due to heating and evaporation of circulating water.

As is clear from fig. 4, although the adhesion rate of the dirt (scale) differs depending on the flow rate and temperature of the circulating water, there is a fixed period td during which the dirt does not adhere to the inside of the heat transfer pipe. This period varies depending on the structure of the equipment, installation environment, operating conditions, and the like, but in the refrigerator shown in the present embodiment, there is almost no tendency for the system performance to deteriorate due to the adhesion of scale during one year after installation. Further, it is understood from this figure that if the adhesion of dirt starts, the dirt coefficient rapidly increases.

Therefore, the reference data creation unit 10B shown in fig. 1 corrects the device characteristic data using, for example, data during the initial one year (hereinafter referred to as "normal data") among the operation data stored in the data collection unit 10A, and creates data of the system performance in a state where there is no degradation of the refrigerator 3 in the entire assumed operation range as the individual characteristic curved surface. The normal data may not necessarily be data of one year, and may be shorter than the normal data and longer than the normal data, as long as data sufficient for creating the individual characteristic surface can be collected.

Thus, the system performance evaluation unit 10C can evaluate the performance of the air conditioner by comparing the operation data (operation data at a time different from the normal data) measured after the acquisition of the normal data with the data of the individual characteristic curved surface. The operation data of the comparison target may include a part of the normal data.

Since the corrected individual characteristic curved surface data is obtained from the actual operation data acquired for each model, it is possible to detect a slight performance deterioration of the refrigerator 3.

Fig. 5 is a flowchart showing data processing performed by the reference data creating unit 10B shown in fig. 1. Hereinafter, a method of creating the individual characteristic curved surface by the reference data creating unit 10B will be described with reference to fig. 5. In the following description, the reference numerals used in fig. 1 and 2 are also attached.

First, in S100, the evaluation parameters input from the input device 14 are acquired, and the normal data is acquired from the data collection unit 10A. In the present embodiment, the evaluation parameters are the duty, COP, and cooling water inlet temperature.

Here, the duty ratio is a ratio of a difference between the cold water inlet temperature sensor 24b and the cold water outlet temperature sensor 24c in the actual operation data to a difference between the maximum cold water inlet temperature and the maximum cold water outlet temperature in the equipment characteristic data. The COP is a value obtained by multiplying the difference between the temperatures obtained by the cold water outlet temperature sensor 24c and the cold water inlet temperature sensor 24b by the measurement value of the cold water flow meter 24a, and by subtracting the difference between the temperatures obtained by the cold water outlet temperature sensor 24c and the cold water inlet temperature sensor 24b from the difference between the temperatures obtained by the cold water inlet temperature sensor 22b and the cold water outlet temperature sensor 22c by the measurement value of the cold water flow meter 22a and multiplying the result by the measurement value of the cold water flow meter 24 a. The cooling water inlet temperature is a measured value of the cooling water inlet temperature sensor 22 b.

Next, in S101, in order to evaluate the system performance, the load factor and the cooling water inlet temperature other than the COP corresponding to the system performance of the refrigerator 3 among the evaluation parameters are classified into the normal data for each of the operation conditions.

Then, in S102, the device characteristic database is acquired from the sub storage device 11. Then, in S103, a correction coefficient for matching the normal data with the device characteristic data is calculated for each operation condition. The correction coefficient is calculated over the entire operation range in the equipment characteristic database by interpolating or extrapolating the correction coefficient for a portion where the operation condition is consistent without normal data according to the operation condition of the refrigerator 3. By calculating the correction coefficient in this way, even when there is a small amount of normal data obtained from refrigerators (actually installed refrigerators) whose installation statuses are different from each other, the correction coefficient in all the operation ranges corresponding to the normal data can be calculated.

Finally, in S104, the individual characteristic curved surface data of the system performance of the actually installed refrigerator 3 without degradation is created by multiplying each data in the equipment characteristic database by the corresponding correction coefficient for each operation condition. This data is not only a data group similar to the equipment characteristic database, but is output from the output unit 10D of the main storage device 10 as a three-dimensional graph of 3 axes in which the load factor, COP, and coolant inlet temperature, which are evaluation parameters, are set to the X axis, Y axis, and Z axis, respectively, and is displayed on the operation data monitor 2 via the output device 15.

Fig. 6 shows an example of the individual characteristic curved surface displayed on the operation data monitor 2.

As shown in the figure, when the cooling water inlet temperature is low and the load factor is high, the COP increases. On the other hand, when the cooling water inlet temperature is high and the load factor is low, the COP decreases.

The evaluation parameters may be constituted by the performance of the refrigerator and items corresponding to the operating conditions, and may be appropriately changed according to a measurement sensor provided in the refrigerator to be evaluated.

In this way, the individual characteristic curved surface data obtained from the equipment characteristic database and the normal data of the refrigerators different from the test refrigerators provided in the building actually performing air conditioning can be used as the approximate data of the accurate refrigerator which becomes the reference in the whole operation range. The individual characteristic curved surface data is reference data in the entire operation range in consideration of installation states such as arrangement of pipes of the refrigerator, inclination of the device, and the like, installation states of a plurality of different measurement sensors and the like for each device, and the like. In addition, the device characteristic database includes a data group in all regions including the required load factor and evaluation parameters calculated from the data group. The data group may further include data under an operating condition with a low load factor, and may be data accurately measured using a design value of a refrigerator before shipment or a refrigerator (testing machine) for testing.

Fig. 7 shows an example of the configuration of the evaluation parameter corresponding to the measurement sensor provided.

Example 1 corresponds to fig. 6. On the other hand, examples 2 and 3 are modification examples.

The evaluation parameter X, Z shown in fig. 7 corresponds to the X-axis and Z-axis of fig. 6, and is an external factor that affects the performance of the air conditioner (refrigerator). On the other hand, the evaluation parameter Y shown in fig. 7 corresponds to the Y axis of fig. 6, and is a parameter that serves as an index for performance evaluation. In other words, the evaluation parameter Y is adjusted according to the relationship with the evaluation parameters X and Z. Thus, the evaluation parameters X, Y and Z are combined into a data group.

The evaluation parameters that are external factors that affect the performance of the air conditioner may be 3 or more.

In short, the individual characteristic curved surface data includes 2 or more evaluation parameters (operating conditions) which are external factors affecting the performance of the air conditioner, and the 2 or more evaluation parameters are adjusted in accordance with the relationship with another evaluation parameter (index for performance evaluation).

In the case of an absorption chiller, the evaluation parameter that is an external factor that affects the performance of the air conditioner may be the inlet temperature of the cooling water or the cooling air excluding the heat generated by at least one of the absorber and the condenser. The evaluation parameter that serves as an index for performance evaluation may be the amount of heat input to the regenerator.

The evaluation parameter, which is an external factor affecting the performance of the air conditioner, may be a function related to the air conditioning load factor.

Next, the method of evaluating the system performance according to the present embodiment will be described.

Fig. 8 is a flowchart showing the processing steps of the system performance evaluation unit 10C according to the present embodiment.

First, in S110, the evaluation target data is acquired from the data collection unit 10A. The evaluation target data is operation data of the refrigerator 3 (fig. 1) for a predetermined period. As a method of specifying the period, an arbitrary evaluation period may be input through the input device 14 in fig. 1, or a setting for automatically performing evaluation in accordance with a fixed period may be adopted. In other words, the evaluation target data is a part of the operation data of the data collection unit 10A.

Next, in S111, the evaluation target data is classified according to the operation conditions. The operating condition is matched with the evaluation parameter of the operating condition of the individual characteristic curved surface, and in the present embodiment, is the cooling water inlet temperature. Then, in S112, the operation condition with the highest frequency of appearance (the most frequent operation condition) in the classified evaluation target data is extracted. Here, in the present embodiment, the most frequent operation condition is the load factor having the highest frequency of occurrence. When the operating condition under which the evaluation target data is classified in S111 is the load factor, the most frequent operating condition is the cooling water inlet temperature with the highest frequency of appearance.

In S113, COP is derived from the evaluation target data at the load factor having a high frequency of appearance extracted according to the cooling water inlet temperature condition, and is set as representative evaluation data. Further, as representative evaluation data, the power consumption used in examples 2 and 3 of fig. 7 may be used instead of the COP. When the COP decreases, it is determined that the performance is deteriorated. On the other hand, when the power consumption increases, it is determined that the performance is degraded. The representative evaluation data is thus an average value of the parameter serving as an index of performance evaluation in the region.

On the other hand, in S114, the individual characteristic curved surface data created by the reference data creation unit 10B is acquired.

Then, in S115, data that matches the operating conditions representing the evaluation data is extracted from the individual characteristic surface data, and set as a reference value. Thus, the reference value is a value of the individual characteristic curved surface data under the operating condition corresponding to the value representing the evaluation data (in the case of fig. 6, a value of the Y axis (COP)).

In S116, the representative evaluation data of S113 and the reference value of S115 are compared. Specifically, the deviation of the evaluation target data from the normal data is calculated. As a result, the system performance evaluation unit 10C accumulates the system performance every time the evaluation is performed, and evaluates the degree of degradation based on the change in the system performance according to the elapsed time. In other words, the data collection unit 10A has a function of accumulating results obtained by comparing the operation data and the individual characteristic curved surface data collected at a plurality of different times by the system performance evaluation unit 10C, and determines a change in performance of the air conditioner using the results.

Finally, in S117, the output is output from the output unit 10D of the main storage device 10 and displayed on the operation data monitor 2 via the output device 15.

In addition, although the deviation is calculated from the evaluation target data in a narrow range within the specified period, it is possible to estimate how much annual power consumption increases, how much the running cost increases, and the like, when the refrigerator is continuously operated without performing maintenance work in order to obtain the correction coefficient corresponding to the normal data for the entire area of the individual characteristic curved surface data. This makes it possible to provide the user with meaningful data regarding the necessity of the maintenance work.

Specifically, since the evaluation parameters in the range of all the operating conditions including the operating condition with a high air-conditioning load factor can be estimated from the correction coefficient using the operating data acquired in spring, autumn, winter, or the like of the operating condition with a low air-conditioning load factor, the degree of the current performance deterioration can be determined in consideration of the annual power consumption, the operating cost, and the like.

More specifically, the estimated value of the operation data in the region where the ratio of the air conditioning load factor to the maximum value is, for example, 50% or less (spring, autumn, winter, etc. in the case of a refrigerator) may be calculated using the data collected in the period where the ratio exceeds 50% with reference to the maximum value of the air conditioning load factor in the period where the air conditioning load factor is high (in the case of a refrigerator, generally, the summer season), and the estimated value may be compared with the individual characteristic curved surface data. The estimated value may be used to calculate annual power consumption, running cost, and the like. The degree of current performance degradation can be determined in consideration of annual power consumption, running cost, and the like. The determination may be performed using data collected during a period in which the ratio is 30% or less.

Fig. 9 shows an example of the evaluation result displayed on the operation data monitor 2.

The evaluation results shown in fig. 9 are evaluation results of system performance corresponding to the data collection timing. Since the data serving as the reference value is different for each evaluation, the evaluation result shows the COP decrease rate (variation) as a fraction.

In this figure, data of COP reduction rate is acquired monthly. The COP decrease rate gradually increased to less than 10 minutes by 11 months in 2005, but increased by 15 minutes or more by 12 months in 2005 and 1 month in 2006. By obtaining such data, it is possible to obtain a material to be investigated for taking a countermeasure such as maintenance work when the COP reduction rate becomes a high value 2 times in succession, for example.

In other words, when the COP decrease rate, which is a value corresponding to a change in the performance of the air conditioner, exceeds a predetermined value a plurality of times, it may be notified that the performance of the air conditioner is degraded.

In the present figure, data for each month is shown, but the present invention is not limited to this, and for example, data for each week may be acquired, and the necessity of maintenance work may be determined using this data.

This makes it possible to accurately obtain small variations in individual refrigerators at a high frequency and to determine deterioration at an early stage.

In addition, the maximum value of the air conditioning load factor is often used as a reference in a period when the air conditioning load factor is high (generally, a summer period in the case of a refrigerator), and the ratio of the air conditioning load factor to the maximum value is often 50% or less (half or less) in a period in spring, autumn and winter in the case of a refrigerator. In such a period, by evaluating the performance using the operation data collected in the period, it is possible to perform maintenance work accompanied by operation stoppage of the air conditioner as necessary without significantly impairing comfort in the building. More preferably, the above ratio is 30% or less.

The performance evaluation server according to the present embodiment produces the following effects.

First, since the individual characteristic curved surface is created for the air conditioner in which the initial system performance differs depending on the installation location and the operating condition even in the same model, the system performance in a state without degradation is obtained in the entire expected operating range, the degree of degradation can be determined using the system performance in a state without degradation under the same operating condition as the evaluation target data as a reference value, and the degradation of the system performance of the air conditioner can be detected in a short time. In other words, the performance deterioration of the air conditioner can be detected earlier.

In addition, although the deterioration detection is performed with high accuracy, the number of measurement sensors is small, and the introduction cost can be suppressed.

In addition, regardless of the operating conditions of the air conditioner, the performance diagnosis can be performed in accordance with the operating conditions of the evaluation target data. Therefore, the performance deterioration can be detected when the cooling load is low, and as a result, the maintenance work accompanying the operation stop of the air conditioner can be performed without impairing the comfort inside the building.

Description of the reference numerals

1: a performance evaluation server; 2: an operational data monitor; 3: a freezer; 10: a main storage device; 10A: a data collection unit; 10B: a reference data creation unit; 10C: a system performance evaluation unit; 10D: an output section; 11: a secondary storage device; 12: an interface; 13: a CPU; 14: an input device; 15: an output device; 20: an electric motor; 21: a turbo compressor; 22: a condenser; 22 a: a cooling water flow meter; 22 b: a cooling water inlet temperature sensor; 22 c: a cooling water outlet temperature sensor; 23: an expansion mechanism; 24: an evaporator; 24 a: a cold water flow meter; 24 b: a cold water inlet temperature sensor; 24 c: a cold water outlet temperature sensor; 25. 28: a water circulation pump; 26: a cooling tower; 26 a: a cooling tower fan; 27: a cooled space.

Claims

1. A performance diagnosis device for an air conditioner, comprising: a data collection unit for collecting and recording operation data of the air conditioner; a device characteristic database which is a data group that collects operation conditions that satisfy the specifications of the air conditioner, the performance diagnosis device diagnosing the performance of the air conditioner,

the performance diagnosis device is characterized by further comprising:

a reference data creating unit that calculates correction coefficients by which the normal data and the equipment characteristic database match each other according to operating conditions, using the evaluation parameters input from the input device of the performance diagnosis device and the normal data, which is the operating data of the air conditioner in a certain period of initial normal operation, included in the data collecting unit, thereby calculating individual characteristic curved surface data; and

a performance evaluation unit for comparing a part of the operation data of the data collection unit with the individual characteristic curved surface data to evaluate the performance of the air conditioner,

the individual characteristic curved surface data is data obtained by correcting the equipment characteristic database so as to correspond to the operation data of the data collection unit,

the performance evaluation unit has a function of comparing the representative evaluation data with a reference value,

the representative evaluation data is an average value of parameters that are used as an index for performance evaluation and that include parameters in a region of the operating condition having the highest frequency of occurrence among the data used by the performance evaluation unit and that are part of the operating data included in the data collection unit,

the reference value is a value of the individual characteristic curved surface data under the operating condition corresponding to the representative evaluation data.

2. The performance diagnostic apparatus for an air conditioner according to claim 1,

a part of the operation data included in the data collection unit and used by the performance evaluation unit are collected at a time different from the operation data used for the calculation of the individual characteristic surface data.

3. The performance diagnostic apparatus for an air conditioner according to claim 1,

the data used by the performance evaluation unit and a part of the operation data included in the data collection unit are collected when the ratio of the air conditioning load factor calculated from the part of the operation data to the maximum value of the air conditioning load factor calculated from the operation data is 50% or less.

4. The performance diagnostic apparatus for an air conditioner according to claim 1,

the performance evaluation unit has the following functions:

an estimated value of the operation data in a region where the ratio of the air-conditioning load factor calculated from the part of the operation data to the maximum value of the air-conditioning load factor calculated from the operation data is 50% or less is calculated using data collected at a time when the ratio of the air-conditioning load factor calculated from the part of the operation data to the maximum value of the air-conditioning load factor calculated from the operation data is 50% or less, and the estimated value is compared with the individual characteristic curved surface data.

5. The performance diagnostic apparatus for an air conditioner according to claim 1,

the individual characteristic curved surface data includes 2 or more evaluation parameters which are external factors affecting the performance of the air conditioner,

the 2 or more evaluation parameters are adjusted according to a relationship with another evaluation parameter.

6. The performance diagnostic apparatus for an air conditioner according to claim 1,

the data collection unit has a function of accumulating results of comparison between the operation data and the individual characteristic surface data collected at a plurality of different times by the performance evaluation unit,

using these results, a change in the performance of the air conditioner is determined.

7. The performance diagnostic apparatus for an air conditioner according to claim 6,

the performance diagnosis device has the following functions: when a value corresponding to the change in the performance of the air conditioner exceeds a predetermined value a plurality of times, the deterioration in the performance is notified.

8. A performance diagnosis apparatus for an air conditioner according to any one of claims 1 to 7,

the air conditioner is of an electric type or a heat-driven type.

9. A method for diagnosing the performance of an air conditioner, which comprises a step of collecting and recording operation data of the air conditioner, and diagnoses the performance of the air conditioner by using an equipment characteristic database which is a data group for collecting operation conditions satisfying the specifications of the air conditioner, the method being characterized by further comprising the steps of:

calculating a correction coefficient by which the normal data and the device characteristic database are matched with each other according to an operation condition using an input evaluation parameter and normal data which is the operation data during a predetermined period of initial normal operation of the air conditioner, thereby calculating individual characteristic curved surface data; and

comparing a part of the operation data of the air conditioner with the individual characteristic curved surface data to evaluate the performance of the air conditioner,

the individual characteristic curved surface data is data obtained by correcting the equipment characteristic database so as to correspond to the operation data of the air conditioner,

comparing the representative evaluation data with a reference value in the step of performing the evaluation of the performance,

the representative evaluation data is an average value of parameters that are indicators of performance evaluation and that include parameters in a region of the operation condition having the highest frequency of occurrence among the collected and recorded operation data and that are used in the step of performing the performance evaluation,